1. Field of the Invention
The present invention relates to an electrically conductive porous body for a fuel cell, to a fuel cell having same, and to a method of manufacturing same.
2. Description of Related Art
A fuel cell is an apparatus that obtains electrical energy, generally using hydrogen and oxygen as fuel. Because the fuel cell is superior with regard to the environment and also achieves a high energy efficiency, fuel cell development is being widely pursued as a future energy supply system. Because a solid polymer fuel cell, among the various types of fuel cells, operates at a relatively low temperature, it has particularly good start-up performance. For this reason, research is being actively conducted in a wide range of fields for the purpose of the practical use thereof.
In a solid polymer fuel cell, current collectors are disposed in intimate contact with both surfaces of a membrane electrode assembly (hereinafter sometimes “MEA”) that is formed by the joining of a catalyst layer to both surfaces of a solid polymer electrolyte membrane. A porous electrical conductor is often used for these current collectors. In order to increase the electrical generation efficiency of the fuel cell, it is necessary to reduce the contact resistance between the current collectors and the membrane electrode assembly. In Japanese Patent Application Publication No. JP-A-2004-71456, there is a disclosure of art for polishing and grinding the surface of a titanium sintered body used as an a current collector. According to this art, it is possible to improve the contact surface area ratio between the current collector and the membrane electrode assembly.
In the above-noted disclosed art, however, when performing polishing and grinding, there is the possibility that the internal condition of the collector changes. In this case, it becomes difficult to control the quality of the current collector.